Question

Coefficient of kinetic friction between $3\text{kg}\text{and}2\text{kg}$ block is $0.25$. The horizontal table surface is smooth. Find the acceleration $($in ${\text{m/s}}^2)$ of block of mass $10\text{kg}$.

• A. $6$
• B. $8$
• C. $2$
• D. $4$

Answer 1

The correct option is A $6$


For $10\text{kg}$,

$10g-T_2=10a.....\left(1\right)$

For $3\text{kg}$,

$T_2-(T_1+\mu N)=3a$

$T_2-T_1-0.25\times 2\times g=3a$

$T_2-T_1-5=3a.........\left(2\right)$

For $2\text{kg}$,

$T_1-0.25\times 2\times g=2a$

$T_1-5=2a.......\left(3\right)$

By solving equation $\left(1\right),\left(2\right)$ and $\left(3\right)$, we get

$10g-5-5=10a+3a+2a$

$90=15a$

$\therefore a=6{\text{m/s}}^2$